Metastasis to the bone marrow is observed in a number of fatal cancers. Tumor cells preferentially migrate to the bone cavity as a function of composition of the bone marrow. We have developed a tissue engineered analogue of the bone marrow and plan to use this construct to identify the key stromal cellular components of a bone marrow metastatic niche. We propose to: 1) Develop a microfluidic platform to capture migratory tumor cells in vitro, 2) Create tumor-stroma microenvironments on-chip, and 3) In vivo comparison and treatment study of BMSC scaffolds on tumor growth. This project will provide essential training to candidate in microfluidics, imaging, and cancer biology during the K99 training period and propel him to be a successful independent investigator in the field of biomaterials and oncology as an R00 investigator at a research university.